U.S. patent application number 15/551944 was filed with the patent office on 2018-03-15 for data transmission method.
The applicant listed for this patent is Media Tek Singapore Pte. Ltd.. Invention is credited to Po-Ying CHEN, Feifei SUN, Min WU, Lei ZHANG.
Application Number | 20180077703 15/551944 |
Document ID | / |
Family ID | 58661827 |
Filed Date | 2018-03-15 |
United States Patent
Application |
20180077703 |
Kind Code |
A1 |
SUN; Feifei ; et
al. |
March 15, 2018 |
DATA TRANSMISSION METHOD
Abstract
Methods for data transmission are provided. A data-transmission
method includes: utilizing a first sub-frame configuration to
generate a first frame structure through a base station in a
wireless communication network; utilizing a second sub-frame
configuration to generate a second frame structure, wherein the
length of each sub-frame in the second sub-frame configuration is
several times the length of a sub-frame in the first sub-frame
configuration; transmitting an indication of the second sub-frame
configuration to some user equipment; and transmitting and
receiving a signal for some user equipment by using the first frame
structure and the second frame structure. The present disclosure
provides a method to support TDD configuration in the narrowband
system and the new wireless system in the future, which improves
system performance.
Inventors: |
SUN; Feifei; (Beijing,
CN) ; ZHANG; Lei; (Beijing, CN) ; WU; Min;
(Beijing, CN) ; CHEN; Po-Ying; (Hsinchu City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Media Tek Singapore Pte. Ltd. |
Singapore |
|
SG |
|
|
Family ID: |
58661827 |
Appl. No.: |
15/551944 |
Filed: |
November 4, 2016 |
PCT Filed: |
November 4, 2016 |
PCT NO: |
PCT/CN2016/104668 |
371 Date: |
August 18, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 5/0064 20130101;
H04L 5/1469 20130101; H04W 4/70 20180201; H04W 88/02 20130101; H04W
72/0446 20130101; H04W 88/08 20130101 |
International
Class: |
H04W 72/04 20060101
H04W072/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 6, 2015 |
CN |
201510759706.0 |
Claims
1. A data-transmission method, comprising: utilizing a first
sub-frame configuration to generate a first frame structure by a
base station in a wireless communication network; utilizing a
second sub-frame configuration to generate a second frame
structure, wherein a length of each sub-frame in the second
sub-frame configuration is several times a length of a sub-frame in
the first sub-frame configuration; transmitting an indication of
the second sub-frame configuration to multiple user equipments
(UEs); and transmitting and receiving a signal for the UEs by using
the first frame structure and the second frame structure.
2. The method as claimed in claim 1, wherein utilizing the second
sub-frame configuration to generate the second frame structure
further comprises: utilizing an uplink parameter to generate an
uplink sub-frame, utilizing a downlink parameter to generate a
downlink sub-frame, and utilizing the uplink parameter and the
downlink parameter to generate a special sub-frame.
3. The method as claimed in claim 2, wherein the special sub-frame
comprises at least two of a downlink symbol, an uplink symbol, and
a guard period.
4. The method as claimed in claim 1, wherein the indicator of the
second sub-frame configuration comprises at least one of a
subcarrier spacing, a symbol length, a cyclic prefix length, a
sampling rate, a number of FFT points, and an offset.
5. The method as claimed in claim 4, further comprising:
determining an offset between starting positions of the second
frame structure and the first frame structure, and generating the
second frame structure according to the offset.
6. The method as claimed in claim 5, wherein the offset between a
starting point of a downlink sub-frame, an uplink sub-frame, and a
special sub-frame as a whole in the second sub-frame configuration
and a starting point of the first sub-frame configuration is
zero.
7. The method as claimed in claim 5, wherein the offset between a
starting point of a downlink sub-frame, an uplink sub-frame, and a
special sub-frame as a whole in the second sub-frame configuration
and a starting point of the first sub-frame configuration is not
zero.
8. The method as claimed in claim 5, wherein starting points of a
downlink sub-frame and an uplink sub-frame in the second sub-frame
configuration have different offsets with respect to starting
points of a downlink sub-frame and an uplink sub-frame in the first
sub-frame configuration.
9. The method as claimed in claim 1, wherein the length of the
sub-frame in the second sub-frame configuration equals the length
of the sub-frame in the first sub-frame configuration multiplied by
a factor, and the factor is two, five, or a power of two.
10. A data-transmission method, comprising: in a wireless
communication network, receiving an induction of a second sub-frame
configuration by a user equipment (UE), wherein a length of each
sub-frame in the second sub-frame configuration is several times a
length of a sub-frame in a first sub-frame configuration; utilizing
the second sub-frame configuration to generate second frame
structures which are different from a sub-frame in the first
sub-frame configuration; and transmitting and receiving a signal
with a base station by using the second frame structures.
11. The method as claimed in claim 10, wherein an uplink and a
downlink between the UE and the base station use different second
frame structures.
12. The method as claimed in claim 10, wherein utilizing the second
sub-frame configuration to generate the second frame structures
further comprises: utilizing an uplink parameter to generate an
uplink sub-frame, utilizing a downlink parameter to generate a
downlink sub-frame, and utilizing the uplink parameter and the
downlink parameter to generate a special sub-frame.
13. The method as claimed in claim 12, wherein the special
sub-frame comprises at least two of a downlink symbol, an uplink
symbol, and a guard period.
14. The method as claimed in claim 10, wherein the second sub-frame
configuration comprises at least one of a subcarrier spacing, a
symbol length, a cyclic prefix length, a sampling rate, a number of
FFT points, and an offset.
15. The method as claimed in claim 14, further comprising:
determining an offset between starting positions of the second
sub-frame configuration and the first sub-frame configuration, and
generating the second frame structure according to the offset.
16. The method as claimed in claim 15, wherein an offset between a
starting point of a downlink sub-frame, an uplink sub-frame, and a
special sub-frame as a whole in the second sub-frame configuration
and a starting point of the first sub-frame configuration is
zero.
17. The method as claimed in claim 15, wherein an offset between a
starting point of a downlink sub-frame, an uplink sub-frame, and a
special sub-frame as a whole in the second sub-frame configuration
and a starting point of the first sub-frame configuration is the
second offset which is not zero.
18. The method as claimed in claim 15, wherein starting points of a
downlink sub-frame and an uplink sub-frame in the second sub-frame
configuration have different offsets with respect to starting
points of a downlink sub-frame and an uplink sub-frame in the first
sub-frame configuration.
19. The method as claimed in claim 10, wherein the length of the
sub-frame in the second sub-frame configuration equals the length
of the sub-frame in the first sub-frame configuration multiplied by
a factor, and the factor is two, five, or a power of two.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to wireless communication and
especially related to the frame structure and slot allocation of a
Time-Division Duplexing (TDD) communication system.
DESCRIPTION OF THE RELATED ART
[0002] With rapid developments being made in the
cellular-mobile-communication industry, the fifth-generation (5G)
mobile-communication system has been receiving more attention and
has had more research conducted on it. Recently, 5G has been
officially named IMT-2020 by ITU, and is expected to enter the
commercial phase in 2020. Unlike traditional 2G/3G/4G
mobile-cellular systems, 5G is not only designed for a human user,
but it also supports various types of Machine Type Communication
(MTC) users. Among business that service MTC terminals, one
business is called Massive MTC (MMC). The main characteristics of
an MTC terminal served by the aforementioned business are: (1) low
cost (the cost of a terminal is much less than a smart phone); (2)
a great amount (according to the requirements of the ITU for 5G,
the MMC business will support 10.sup.6 connections per square
kilometer); (3) low data rate requirements; and (4) a high
tolerance for latency, etc.
[0003] In the Narrow Band Internet of Things (NB IoT) project which
is a new project in the standardization phase of LTE Release 13,
the bandwidth of the terminal RF is further reduced to 180 KHz. In
order to be successively deployed in various scenarios, the NB IoT
project presents three deployment scenarios, which are the in-band
deployment, guard band deployment, and stand-alone deployment.
Since the bandwidth of the terminal RF is further reduced, the
accuracy of the time-frequency synchronization is affected. For the
purpose of guaranteeing the performance without having any
additional overhead, a carrier which is smaller than the normal
LTE-subcarrier spacing to the uplink design has been considered. A
way of making the small subcarrier compatible with the LTE system,
and especially compatible with TDD system, is an urgent problem
that must be solved.
[0004] In view of the above description, embodiments of the present
disclosure provide a method of generating a frame structure and
provide the user equipment and base station corresponding to the
method.
BRIEF SUMMARY OF THE INVENTION
[0005] One embodiment of the present disclosure provides a
data-transmission method, and the method comprises utilizing a
first sub-frame configuration to generate a first frame structure
by a base station in a wireless communication network; utilizing a
second sub-frame configuration to generate a second frame
structure, wherein the length of each sub-frame in the second
sub-frame configuration is several times the length of a sub-frame
in the first sub-frame configuration; transmitting an indication of
the second sub-frame configuration to some user equipment; and
transmitting and receiving a signal for some user equipment by
using the first frame structure and the second frame structure.
[0006] Another embodiment of the present disclosure provides a
data-transmission method, and the method comprises receiving an
induction of a second sub-frame configuration through user
equipment in a wireless communication network, wherein the length
of each sub-frame in the second sub-frame configuration is several
times the length of a sub-frame in a first sub-frame configuration;
utilizing the second sub-frame configuration to generate a second
frame structure which is different from a sub-frame in the first
sub-frame configuration; and transmitting and receiving a signal
with a base station by using the second frame structure.
[0007] The present disclosure further provides a base station and
user equipment which use the methods mentioned above.
[0008] By using the data-transmission method and the user equipment
provided by the present disclosure, the base station can support
TDD in the narrowband system and the new wireless system in the
future, which improves system performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present disclosure can be more fully understood by
reading the subsequent detailed description and examples with
references made to the accompanying drawings, and the same number
in the drawings represents the similar components, wherein:
[0010] FIG. 1 is a block diagram of a wireless communication system
according to one embodiment of the present disclosure.
[0011] FIG. 2 is a frame structure design and an UL-DL
configuration of a LTE TDD system according to one embodiment of
the present disclosure.
[0012] FIG. 3 is a first frame structure according to one
embodiment of the present disclosure.
[0013] FIG. 4 is a design for a TDD system according to one
embodiment of the present disclosure.
[0014] FIG. 5 is a design of a first set of special M sub-frames
according to one embodiment of the present disclosure.
[0015] FIG. 6 is a corresponding relation diagram of the special
sub-frame configuration of the legacy system and the new-design M
special sub-frame according to one embodiment of the present
disclosure.
[0016] FIG. 7 is a second design for the TDD system according to
one embodiment of the present disclosure.
[0017] FIG. 8 is a third design for the TDD system according to one
embodiment of the present disclosure.
[0018] FIG. 9 is a second frame structure according to one
embodiment of the present disclosure.
[0019] FIG. 10 is a design of a second set of special M sub-frames
according to one embodiment of the present disclosure.
[0020] FIG. 11 is a design of a third set of special M sub-frames
according to one embodiment of the present disclosure.
[0021] FIG. 12 is a design of a fourth set of special M sub-frames
according to one embodiment of the present disclosure.
[0022] FIG. 13 shows the correlation between a design of a fourth
set of special M sub-frames and the legacy TDD downlink
configuration according to one embodiment of the present
disclosure.
[0023] FIG. 14 is a flow diagram illustrating how the network side
generates the updated frame structure which is applied to different
user equipments according to one embodiment of the present
disclosure.
[0024] FIG. 15 is a flow diagram illustrating the method of
receiving and transmitting a signal at the user side according to
one embodiment of the present disclosure.
[0025] FIG. 16 is another flow diagram illustrating the method of
receiving and transmitting a signal at the user side according to
one embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0026] According to the accompanying drawings and the following
description, the mentioned features and other features of the
embodiments of the present disclosure are obvious. These
embodiments are used for illustrating, and the present disclosure
is not limited to these embodiments. In order to make those skilled
in the art easily understand the principles and embodiments of the
present disclosure, the embodiments of the present disclosure are
described by taking LTE carrier and the Massive Machine Type
Communication (MMC) carrier as examples. It should be understood
that the embodiments of the present disclosure are not limited to
the applications described above. For the operation mode
determining other applications, the embodiments of the present
disclosure are also applicable.
[0027] In the new project on the new Internet of Things (IoT)
terminal in Release 13 of Long Term Evolution (LTE), the minimum RF
bandwidth of IoT terminal may be 180 KHz. One advantage of this
evolution is that the cost of the RF can be further reduced.
Another advantage is that such system bandwidth and transmission
bandwidth options help to find more deployment spectrum for the IoT
(e.g. MTC) applications. For example, GSM system will gradually be
withdrawn from commercial operation in the near future. The 180 KHz
bandwidth is compatible with the legacy GSM system. Therefore, it
is easy to deploy the MTC carrier supporting 180 KHz bandwidth in
the legacy GSM band during the process through which the GSM is
gradually withdrawn. Such an MTC carrier is a separate MTC carrier
which is transmitted or received on a separate carrier (also
referred to as a spectrum or frequency band) as a stand-alone
deployment. On the other hand, the actual transmission bandwidth in
180 kHz is consistent with the minimum transmission unit resource
block (RB) of the LTE system, if an MTC carrier can be deployed in
the LTE system and utilized to coexist with the original
public/dedicated channel and signal of LTE system. Transmission or
reception within another system band and within a range, which is
less than another system bandwidth, is known as an in-band
deployment. Furthermore, an MTC carrier supporting a bandwidth of
the order of 180 kHz may also be deployed on the LTE system guard
band. For example, the modulation and the numerology of LTE may be
maintained, and the original LTE bandwidth may be extended to the
guard band with one or more RB to be used as the MTC carrier. In
another example, a new modulation (e.g., single carrier modulation)
or a parameter that is different from the legacy LTE may be applied
on the guard band to operate as the MTC carrier, such as a
different subcarrier spacing, which makes its MASK meet the
requirements of the protocol via filtering. The transmission or
reception on the guard band of another system is called a
guard-band deployment. These methods will provide greater
flexibility for future MTC deployments and help the MTC industry
develop well.
[0028] The present disclosure provides a frame structure design for
an MTC carrier supporting 180 kHz bandwidth, especially for in-band
and guard-band deployments and particularly for LTE time division
duplex (TDD) systems, allowing narrowband systems to operate in the
broadband system, which can provide MTC services on the LTE TDD
carriers and contribute to the industrialization of IoT.
[0029] Furthermore, the future 5G communication system may be
composed of a variety of transmission formats, and different frame
structures may be designed to meet different needs. For example, a
frame structure supports ultra-reliable requirements, a frame
structure supports high-speed requirements (e.g., wide band LTE
systems, millimeter-wave (mmWave or mmW) systems), a frame
structure supports the ultra-low latency, and a frame structure
supports massive IoT devices, and the like. Different frame
structures can be compatible and can be deployed in the same
frequency band; furthermore, different frame structures can be
flexibly switched according to different demands. The method of the
present disclosure is applicable to 5G communications, or can be
utilized to solve the coexistence problems of 4G and 5G
communication systems.
[0030] The above-mentioned applications are embodiments of the
present disclosure, and the present disclosure is not limited
thereto.
[0031] FIG. 1 is a schematic block diagram of a wireless
communication system according to one embodiment of the present
disclosure. The wireless communication system 100 includes one or
more basic elements 101 and 102 that form one or more access
networks 110 and 120 distributed within a geographic region. The
access networks 120 and 110 may be Universal Terrestrial Radio
Access Network (UTRAN) of WCDMA technology, or E-UTRAN of LTE/LTE-A
technology, or GSM/GPRS technology. The basic elements may also be
known as an access point, base station node B, evolved Node B
(eNB), or other terms in the art. In some systems, one or more base
stations are coupled to the controller to form an access network
which is communicated with one or multiple core network.
[0032] As shown in FIG. 1, one or more user equipment (UE) 103 and
104 are wirelessly coupled to base stations 101 and 102 for
operating in a service area (e.g., a wireless service is obtained
within a cell or a cell sector.). A UE may be called user equipment
(UE), a wireless communication device, a terminal, or other term.
Although the UE 103 in FIG. 1 is illustrated as a hand-held
terminal, the UE 103 is not limited to being a hand-held terminal.
The UE 103 may be a non-handheld terminal, an IoT terminal, or a
large-scale device. The UE 103 transmits UL data to the base
station 101 by the UL channel 111 in the time and/or frequency
domain. The UE 104 transmits UL data to the base station 102 by the
UL channel 114 in the time and/or frequency domain. The base
stations 101 and 102 transmit the DL signals to the UE 103 and 104
by the DL channels 112 and 113, respectively. In one embodiment,
the system may utilize OFDMA technology or multicarrier technology
on a DL communication, and the communication system may use a
next-generation single-carrier (SC) technology based on OFDMA
technology or FDMA architecture or another single-carrier
technology on a UL communication, such as single-carrier technology
based on GMSK modulation, and the like.
[0033] FIG. 1 further illustrates a simplified block diagram of the
UE 103 and the base station 101 according to the described
embodiment of the present invention. The base station 101 has an
antenna 126 that transmits and receives wireless signals. An
RF-transceiver module 123 coupled to the antenna receives an RF
signal from the antenna 126, converts the RF signal into a baseband
signal, and transmits the signal to the processor 122. The
RF-transceiver module 123 also converts the baseband signal
received from the processor 122 into an RF signal and sends the RF
signal to the antenna 126. The processor 122 processes the received
baseband signals and invokes different functional blocks to
implement the functions of the base station 101. The memory 121
stores program instructions and data 124 to control the operation
of the base station 101.
[0034] In accordance with one embodiment of the present disclosure,
the base station 101 further comprises other functional modules for
implementing embodiments of the present disclosure. For example,
the base station 101 includes a frame-structure generator 125 for
generating a first frame structure according to a set of
parameters, wherein the first frame structure includes downlink
sub-frame(s), uplink sub-frame(s), and special sub-frame(s). The
frame-structure generator 125 further generates a second frame
structure according to a second set of parameters, wherein at least
one of the three kinds of sub-frames of the downlink sub- frame,
the uplink sub-frame, and the special sub-frame in the second frame
structure is different from a corresponding sub-frame in the first
frame structure. The base station further utilizes the
RF-transceiver module 123 to apply the first frame structure and
the second frame structure to different users. Only some of the
modules for implementing the embodiments of the present disclosure
are mentioned above. The modules may be implemented by hardware,
software, firmware, or a combination of any of the above, and the
present disclosure is not limited thereto.
[0035] The UE 103 has an antenna 135 which transmits and receives
wireless signals. An RF-transceiver module 134 coupled to the
antenna, receives an RF signal from the antenna 135, converts the
RF signal into a baseband signal, and transmits the signal to the
processor 132. The RF-transceiver module 134 also converts the
baseband signal received from the processor 132 into an RF signal,
and sends the RF signal to the antenna 135. The processor 132
processes the received baseband signal and invokes the different
functional modules to implement the functions in the UE 103. The
memory 131 stores program instructions and data 136 to control the
operation of the UE 103.
[0036] In accordance with one embodiment of the present disclosure,
the UE 103 further comprises other functional modules for
implementing embodiments of the present disclosure. The UE 103
utilizes the RF-transceiver module 134 to receive an indication of
a first UL-DL configuration and an indication of a first special
sub-frame configuration. The UE further comprises a
DL-UL-configuration-detection-and-generation circuit 191 for
generating a frame structure based on the indication of the first
uplink-and-downlink configuration, the indication of the first
special sub-frame configuration, the mapping relationship between
the first uplink-and-downlink configuration and a second
uplink-and-downlink configuration, and the mapping relationship
between the first special sub-frame configuration and a second
special sub-frame configuration. Embodiments of the new DL-UL
configuration are further described in the following examples. Only
a part of the modules for implementing the embodiments of the
present disclosure are mentioned above. The modules may be
implemented by hardware, software, firmware, or a combination of
any of the above, and the present disclosure is not limited
thereto.
[0037] FIG. 2 shows the frame structure design and the UL-DL
configuration in the LTE TDD system. As shown in FIG. 2, in the LTE
system, the length of the radio frame of TDD and FDD system is 10
ms. The radio frame includes 307200 samples (i.e.,
T.sub.f=307200.times.T.sub.s=10 ms). Each radio frame comprises two
half frames whose length is 153600.times.T.sub.s=5 ms. Each half
frame contains five sub-frames, and the length of each sub-frame is
30720.times.T.sub.s=1 ms. The UL-DL configurations supported by the
present disclosure are listed in FIG. 2. Regarding each sub-frame
of the wireless frame, "D" represents the sub-frame for DL
transmission; "U" represents the sub-frame for UL transmission; and
"S" represents the special sub-frame. The special sub-frame has
three special slots, which are downlink-pilot-time slot (DwPTS),
guard period (GP), and uplink-pilot-time Slot (UpPTS). FIG. 2 shows
the length of DwPTS and UpPTS, which is in the condition that the
total length of the DwPTS, GP and UpPTS is equal to
30720.times.T.sub.s=1 ms. Each sub-frame i is defined as comprising
two time slots (i.e., 2i and 2i+1), and the length of one slot in
each sub-frame is T.sub.slot=15360.times.T.sub.s=0.5 ms. The UL-DL
configuration, which has downlink-to-uplink switch-point
periodicity with 5 ms and 10 ms, is supported in the legacy system.
In the case of a 5 ms DL-UL switch-point periodicity, each half
frame has the special sub-frame, such as UL-DL configurations 0, 1,
2, and 6 in FIG. 2. In the case of a 10 ms DL-UL switch-point
periodicity, only the first half frame has the special sub-frame,
such as UL-DL configurations 3, 4 and 5 in FIG. 2. Reserved
sub-frame 0, sub-frame 5 and DwPTS are used for DL transmission.
The UpPTS and the sub-frames after the special sub-frame are
reserved for UL transmission, as shown in FIG. 2.
[0038] FIG. 3 is a first frame structure according to one
embodiment of the present disclosure. The subcarrier spacing is
3.75 kHz. The 64-point Fast Fourier transform (FFT) is adopted. The
number of available carriers is 48 (i.e., occupying a 180 kHz
bandwidth). The sampling frequency is T.sub.Ms=64.times.3.75
kHz=240 kHz. As shown in FIG. 3, the length of an MTC sub-frame or
an M-sub-frame (hereinafter denoted as M sub-frame) is 2 ms, and
the M sub-frame includes 7 symbols. In one embodiment, the length
of the cyclic prefix (CP) of the first symbol is equal to eight
samples (i.e., about 33.3 .mu.s), and the length of the CP of each
symbol of the last six symbols is equal to four samples (i.e.,
about 16.7 .mu.s). In order to obtain the same wireless-frame
length as another system (such as 10 ms), in the disclosed
embodiment, an updated frame (denoted as an M frame) represents a
frame used in an MTC UE or an IoT UE, and the M frame is composed
of 5 M sub-frames. The representations of the M frame and the M
sub-frame are used to describe the frame and sub-frame which are
different from the frame and sub-frame of the legacy LTE system,
and the present disclosure is not limited to the MTC UE. A system
to which the M frame and the M sub-frame are applied is not limited
to the MTC or IoT system. In another embodiment, an M frame may be
designed to be longer so that the UE can read information only when
the UE wakes up at the frame header of each M frame, to quickly
know whether the M frame transmits the UE information. If there is
no UE information, then the UE can enter the sleep state and
achieve the effect of power saving. For example, one M frame is
designed to be 80 ms, 160 ms, or even 320 ms. Moreover, a
superframe may be introduced. A superframe consists of a number of
M frames. As described above, a superframe may be used to define
the UE to read paging information. For example, a UE read the
paging information only in the specific position within a
superframe. If there is no paging information, then the sleep state
is continued and the effect of power saving is achieved. In another
embodiment, CP length for the first 4 symbols is 5 samples (i.e.,
about 20.83 .mu.s), and CP length for the remaining 3 symbols is 4
samples (i.e., about 16.7 .mu.s). In addition, the lower part of
FIG. 3 shows a comparison between the new designed frame structure
and the frame structure of the legacy LTE system. An M sub-frame is
2 ms and includes 7 symbols corresponding to two LTE sub-frames. A
legacy LTE sub-frame contains 14 OFDM symbols per sub-frame for a
normal CP, and the sub-frame contains 12 OFDM symbols for an
extended CP. In other words, since the new frame structure design
uses 2 ms as a unit, a new design needs to be applied to the TDD
system. It will be understood by those skilled in the art that the
TDD configuration for designing a new system frame structure using
2 ms as a unit is only one illustration. Without departing from the
spirit of the present disclosure, the TDD configuration using the
power of 2 as a unit may also be applied in accordance with the
above principles.
[0039] FIG. 4 is a schematic diagram of a first sub-frame
configuration design applied to a TDD system according to one
embodiment of the present disclosure. As shown in FIG. 4, M
sub-frame #0 starts from the legacy sub-frame #0 of the legacy
configuration: that is, M sub-frame #0 is the legacy sub-frame #0
and legacy sub-frame #1, and M sub-frames #1 corresponds to the
legacy sub-frame #2 and legacy sub-frame #3. Similarly, M
sub-frames #2, #3, and #4 correspond to the legacy sub-frames #4
and #5, sub-frames #6 and #7, and sub-frames #8 and #9,
respectively. In TDD system, the UL-DL configuration has multiple
configurations, as shown in FIG. 2. For the in-band deployment, the
directions of the uplink and downlink of the M sub-frame should be
the same as the directions of the uplink and downlink of the legacy
system. Therefore, if the directions of the uplink and downlink of
the legacy sub-frame corresponding to an M sub-frame are changed or
there is a special sub-frame, then the M sub-frame should also be a
special sub-frame. In one embodiment, three special M sub-frame
designs are required for the legacy 7 UL-DL configurations of the
LTE TDD system. As shown in FIG. 4, in design option 1, the
sub-frame of the updated configuration is twice the sub-frame of
the legacy configuration. The timing of the start sub-frames of the
updated configured and the legacy configuration are the same: that
is, the offset between the starting points of the whole updated
configuration and the legacy configuration is zero. Specifically,
if both sub-frames of the legacy configuration are U and U, then
the updated configuration is U. If both sub-frames of the legacy
configuration are D and D, then the updated configuration is D. The
three special sub-frame designs are S0, S1 and S2, respectively.
The design principles are that if the legacy configurations are D
and S, then the updated configuration is S0; if the sub-frames in
the legacy configuration are S and U, then the updated
configuration is S1; if the sub-frames in the legacy configuration
are U and D, then the updated configuration is S2. There are three
special M sub-frames S0, S1, and S2 in this embodiment.
[0040] FIG. 5 shows a schematic diagram of a design of a special M
sub-frame corresponding to the design option 1 according to one
embodiment of the present disclosure. The special M sub-frame 0 is
composed of one or more downlink symbols and the guard period (GP),
wherein one or more downlink symbols form DwPTS as shown in (A).
The special M sub-frame 0 may correspond to an legacy downlink
sub-frame and an legacy special sub-frame, as shown in (B). The
special M sub-frame 1 is composed of one or more downlink symbols,
the GP, and one or more uplink symbols (i.e., DwPTS, GP and UpPTS).
As shown in (A). The special M sub-frame 2 consists of one or more
uplink symbols, a GP, and one or more downlink symbols (i.e.,
UpPTS, GP, and DwPTS), as shown in (A). The GP is existed because M
sub-frame and the legacy sub-frame cannot perform the same
uplink-to-downlink conversion. To avoid generating interference,
there is a need to sacrifice some resources to act as the GP. If
there is an advanced receiver, the GP in this special M sub-frame 2
may not exist, i.e., there are only some uplink symbols and some
downlink symbols. In another embodiment, the special M sub-frame 2
corresponds to several uplink symbols and one legacy downlink
sub-frame, and does not have the GP.
[0041] FIG. 6 is a correspondence diagram of a special sub-frame
configuration of an legacy system and a newly designed M special
sub-frame according to one embodiment of the present invention.
Further examining the legacy sub-frame design, the special
sub-frame has nine configurations. As shown in FIG. 6, DwPTS has 5
kinds of length for the normal CP length; for the extended CP
length, the DwPTS has 4 kinds of length, and the corresponding
UpPTS and the GP have 2 kinds of lengths. Considering that the
symbol length and CP length correspond to a 3.75 kHz carrier
spacing, the DwPTS length of the configuration 0 and configuration
5 in the normal CP length cannot carry one symbol length in the
3.75 kHz carrier spacing frame structure, and the DwPTS length of
the configuration 4 can carry the length of three CP in 3.75 kHz
and one symbol. The other configurations (i.e., configurations 1,
2, 3, 6, 7, and 8) correspond to 2 downlink symbols. Similarly, for
the extended CP length setting, the DwPTS of configuration 0 to
configuration 6 correspond to 0, 2, 2, 3, 0, 2, and 2 symbols,
respectively. FIG. 6 shows the mapping between the M special
sub-frames and the legacy special sub-frame configurations, where
T.sub.Ms is the sampling frequency of the newly designed M frame
structure.
[0042] FIG. 7 is a schematic diagram of a design of a second
sub-frame configuration applied to a TDD system according to
another embodiment of the present invention. As shown in FIG. 7, in
design option 2, one sub-frame in the updated configuration is
twice the sub-frame in the legacy configuration. Unlike FIG. 4, in
Design Option 2, the timing of the starting sub-frame of the whole
updated configuration and the timing of the starting sub-frame of
the legacy configuration are different: that is, the offset between
the starting points of the whole updated configuration and the
legacy configuration is not zero. Specifically, the M sub-frame #0
starts from the legacy sub-frame #9 of the legacy configuration,
i.e., the M sub-frame #0 corresponds to the legacy sub-frame #9 and
the legacy sub-frames #0; the M sub-frame #1 corresponds to the
legacy sub-frame #1 and legacy sub-frame #2. Similarly, the M
sub-frames #2, #3 and #4 correspond to the legacy sub-frames #3 and
#4, the sub-frames #5 and #6, and sub-frames #7 and #9,
respectively. For an in-band deployment, the uplink and downlink
directions of an M sub-frame are the same as the uplink and
downlink directions of an elegacy system. Therefore, if the
directions of the uplink and downlink of the legacy sub-frame
corresponding to an M sub-frame are changed or there is a special
sub-frame, then the M sub-frame should also be a special sub-frame.
The schematic diagram of the special sub-frames shown in FIG. 5 is
also applicable to the updated sub-frame configuration in FIG. 7.
For example, the updated configuration 0 corresponding to legacy
configuration 0 consists of S2 S1 U S0 U. Other configurations are
shown in FIG. 7.
[0043] Compared to the updated configuration in FIG. 4, one
advantage of the content in FIG. 7 is that the updated
configuration adds the M sub-frame utilized for downlink (D), which
reduces the number of special sub-frames, increases the sub-frame
for the downlink transmission, and makes the more sub-frame
configuration useful for an effective transmission.
[0044] In another embodiment, for an legacy configuration 1, the
uplink and downlink configurations are DSUUDDSUUD, and the two
special sub-frames may be skipped as the guard periods, and an
uplink M sub-frame and a downlink M sub-frame are between the two
special sub-frames. Therefore, there are 2 uplink M sub-frames and
2 downlink M sub-frames (i.e., D GP U D GP U, where GP is 1 ms) in
10 ms.
[0045] FIG. 8 is a schematic diagram of a design of a third
sub-frame configuration applied to a TDD system according to
another embodiment of the present invention. As shown in FIG. 8, in
Design Option 3, one sub-frame in the updated configuration is
twice the sub-frame in the legacy configuration. Unlike FIG. 4 and
FIG. 7, in Design Option 3, the condition is not that there is an
offset between the starting sub-frames of the whole updated
configuration and the legacy configuration, but the updated
sub-frame U or D in the updated configuration has a starting point
that is different from the starting point of the sub-frame U or D
in the legacy configuration, respectively (i.e., the offsets are
different). Specifically, as shown in the upper half of FIG. 8, the
DS sub-frame in the legacy configuration corresponds to the D
sub-frame in the updated configuration, and both the sub-frames SU
and UU in the legacy configuration correspond to the U sub-frame in
the updated configuration, or the sub-frame SU and the sub-frame UU
in the legacy configuration correspond to the S sub-frame and the U
sub-frame in the updated configuration, respectively. In other
words, the D sub-frame in the updated configuration and the D
sub-frame in the legacy configuration have the same offset
regarding the starting sub-frame, and the U sub-frame in the
updated configuration has the same offset as the U sub-frame in the
legacy configuration. The offsets in the above two updated
configurations are different. That is, the U sub-frames and the D
sub-frames in the updated configuration have different offsets, and
the condition is not that the U sub-frames and the D sub-frames as
a whole have an offset with the legacy configuration.
[0046] In one embodiment, DL and UL are respectively defined at the
sub-frame level. For example, the legacy configuration 0 defines 6
M sub-frames, which are 2 downlink M sub-frames and 4 uplink M
sub-frames, wherein the downlink M sub-frames are special
sub-frames only having a part of symbols (i.e., only DwPTS is
transmitted). Uplink M sub-frame #0 and uplink sub-frame #2 are
special sub-frames, and only have partial symbols (i.e., only UpPTS
are transmitted). In another embodiment, regarding the 6 M
sub-frames defined by the legacy configuration 2, two downlink
sub-frames (downlink M sub-frames #0 and downlink M sub-frames #2)
are special sub-frames, and only partial symbols are transmitted
(i.e., DwPTS sub-frame). Similarly, two uplink M sub-frames are
also special sub-frames, and only UpPTS is transmitted. In another
embodiment, to maintain the same number of logical sub-frames as
the actual resource, the uplink and downlink M sub-frames are
defined as the shifts of the original sub-frames. For example, the
M sub-frames of the legacy configuration 0 are defined as the
downlink M sub-frames, which are the M sub-frame #0 and M sub-frame
#2 shifting right by 1 ms (-1 ms); and defined as the uplink M
sub-frames, which are M sub-frame #0 shifting right by 1 ms (-1
ms), M sub-frame #1 shifting right by 1 ms (-1 ms), M sub-frame #3,
and M sub-frame #4. In another embodiment, the M sub-frames of the
legacy configuration 2 are defined as the downlink M sub-frames,
which are the M sub-frames #0, M sub-frames #1 -1 ms, M sub-frames
#2 -1 ms, and M sub-frames #5, and defined as the uplink M
sub-frame, which are the M sub-frame #0 -1 ms and M sub-frame
#4.
[0047] FIG. 9 is a schematic diagram of a second frame structure
according to one embodiment of the present invention. The
subcarrier spacing is 2.5 kHz using a 128-point Fast Fourier
Transform (FFT) and 72 available carriers, i.e., occupying a 180
kHz bandwidth, and the sampling frequency is T.sub.Ms=128.times.2.5
kHz=320 kHz. As shown in FIG. 9, an M sub-frame (M-sub-frame) is 5
ms and includes 12 symbols. That is, the length of the M sub-frame
in the updated configuration is five times the length of the
sub-frame in the legacy configuration. In one design, a cyclic
prefix (CP) length of the first M symbol has nine samples, which is
28.125 us. The CP length of the last 11 M symbols is five samples
(i.e., about 15.625 us). In order to have the same wireless frame
length as the other system, (such as 10 ms), in the disclosed
embodiment, an updated frame (herein as M frame) is represented as
the frame applied to MTC UE or IoT UE. Furthermore, the M frame
consists of 2 M sub-frames, or consists of an M frame which further
shift to right by n M sub-frames to obtain the longer wireless
frame. For the purpose of making the length of the wireless frame
be integral times more than 10 ms, n should be an even number. In
another embodiment, a CP length of the first 4 M symbols have is 6
samples (i.e., about 18.75 us), and a CP length for the remaining 8
M symbols is 5 samples (i.e., about 15.625 us). In addition, FIG. 9
also shows a comparison between the newly designed frame structure
and the legacy LTE system frame structure. One M sub-frame is 5 ms
and contains 12 symbols corresponding to 5 LTE sub-frames, wherein
each sub-frame for the normal CP includes 14 OFDM symbols, and each
sub-frame for the extended CP includes 12 OFDM symbols. In other
words, since the new frame structure design uses 5 ms as a unit, a
new design needs to be applied to the TDD system.
[0048] FIG. 10 is a schematic diagram illustrating the design of a
special M sub-frame according to one embodiment of the present
disclosure. Referring to FIG. 9, one sub-frame in the updated
configuration occupies 5 ms, corresponding to 5 sub-frames in 5 ms
of the legacy configuration. Therefore, there are three
configurations in the legacy configuration in 5 ms, which are
DSUUU, DSUUD and DSUDD. For these three legacy configurations, FIG.
10 shows the design of the three special M sub-frames. S0 is a
first special M sub-frame consisting of the DwPTS0, GP0, and UpPTS.
S1 is a second special M sub-frame consisting of the DwPTS0, GP0,
UpPTS, GP1 and DwPTS1 with 2 symbols. S2 is a third special M
sub-frame consisting of DwPTS0, GP0, UpPTS, GP1 and DwPTS1 with 4
symbols. S1 and S2 may be regarded as one type of the special M
sub-frame, but the numbers of symbols in the UpPTS and the second
DwPTS1 are different. The GP1 in the second and third special M
sub-frames is used to fill in the gap between DwPTS1 and the
downlink sub-frame of the legacy system. GP1 may be greater than
the number of the sampling point given in FIG. 10. When the number
of the sampling point of GP1 is greater than the number of the
sampling point given in FIG. 10, which means that UpPTS being
transmitted early. Correspondingly, the number of sampling points
of the GP0 is reduced. The number of sampling points of GP0 is
adjusted according to the number of DwPTS, UpPTS, and GP1 so that
the overall special M sub-frame is 5 ms.
[0049] Corresponding to both the legacy uplink and downlink
configurations, the new TDD configuration 2 is SS or SD. The SS
corresponds to configurations 0, 1, 2, and 6 of the legacy
configurations, and the SD corresponds to configurations 3, 4, and
5 of the legacy configurations. More specifically, the legacy
configuration 0 corresponds to S0 S0, and the legacy configuration
1 corresponds to S1 S1; the legacy configuration 2 corresponds to
S2 S2; the legacy configuration 6 corresponds to S0 S1; and the
legacy configurations 3, 4, and 5 correspond to S0D, S1D, and
S2D.
[0050] For NB-IoT or other systems, different waveforms may be used
for the uplink and downlink, or different parameters may be used,
such as a subcarrier spacing or carrier spacing. For example, the
downlink uses subcarrier spacing of 15 kHz, and the uplink uses
small subcarrier spacing (e.g., 3.75 kHz or 2.5 kHz). In such
cases, the frame structures of the uplink and downlink may be
different. For example, for the downlink, one M sub-frame may
consist of a number of sub-frames, while for the uplink, there is
no concept of sub-frames, and there is an M sub-frame directly
consists of a number of symbols. In one embodiment, the downlink
may adopt the legacy configuration and the uplink may adopt the new
configuration.
[0051] FIG. 11 is a schematic diagram showing the design of the
third set of special M sub-frames according to one embodiment of
the present disclosure. In FIG. 11, a downlink M sub-frame is
defined as at least one legacy downlink sub-frame and one legacy
special sub-frame. For the uplink, only the definition of M
sub-frames is used. If there exists only a plurality of uplink
symbols in a special M sub-frame, then they are defined as the
UpPTS of the special M sub-frame. As shown in FIG. 11, a special M
sub-frame S0 corresponding to the legacy configuration DSUUU is
composed of one downlink sub-frame, one DwPTS, one GP, and one
UpPTS. The special M sub-frame S1 corresponding to the legacy
configuration DSUUD consists of one downlink sub-frame, one DwPTS,
one GP, one UpPTS, and one downlink sub-frame. The special M
sub-frame S2 corresponding to the legacy configuration DSUDD is
composed of at one downlink sub-frame, one DwPTS, one GP, one
UpPTS, and two downlink sub-frames. The length of the UpPTS is the
same as the UpPTS shown in FIG. 10. The DwPTS is the same as the
legacy system, such as a configuration of DwPTS corresponding to
the legacy special sub-frame configuration shown in FIG. 6.
[0052] FIG. 12 shows a schematic diagram of a design of a fourth
set of special M sub-frames according to one embodiment of the
present disclosure. As shown in part (A), the special M sub-frames
in this set are respectively composed of one DwPTS, one GP and one
UpPTS. The different configurations correspond to the number of
symbols in DwPTS and UpPTS. For example, there are 2-4 symbols in
the DwPTS of the special M sub-frame S0, which respectively
correspond to the configuration in DwPTS0 in FIG. 10. There are 5
symbols in the DwPTS in the special M sub-frame S1. There are 7-9
symbols in the DwPTS in the special M sub-frame S2. There are 7
downlink M symbols in DwPTS of the special M sub-frame S2
corresponding to the legacy special sub-frame configuration normal
downlink CP configurations 0 and 5 and the legacy configuration
extended downlink CP configurations 0 and 4. There are 8 downlink M
symbols in the special M sub-frame S2 corresponding to the legacy
special sub-frame configuration normal downlink CP configurations
1, 2, 6, and 7 and the extended downlink CP configurations 1, 2, 5,
and 6, and there are 9 downlink M symbols in the special M
sub-frame S2 corresponding to the remaining configuration. The
UpPTS respectively corresponds to the UpPTS configuration shown in
FIG. 10.
[0053] In another embodiment, as shown in part (B) of FIG. 12, the
special M sub-frames respectively consist of a plurality of the
legacy downlink sub-frame (one in S0, two in S1, and three in S2),
one legacy DwPTS, one GP, and one UpPTS. The legacy DwPTS
configuration can be configured as the DwPTS of the legacy special
sub-frame configuration shown in FIG. 6. The UpPTS configuration
may be the configuration of the UpPTS shown in FIG. 10.
[0054] FIG. 13 illustrates a relationship between the design of the
special M sub-frame in FIG. 9 and the legacy TDD downlink
configuration according to one embodiment of the present
disclosure. The embodiment is configured as the configurations of
the uplink and downlink of the legacy TDD after having shifted. The
starting points of the 0th sub-frame of the updated configuration
and the legacy configurations of the configurations 0 and 3 are the
same: that is, the starting point of the M sub-frame #0 is the
legacy sub-frame #0. There is one sub-frame (2 ms) shift between
the legacy configurations of the configurations 1, 4 and the
starting point of the 0th sub-frame of the updated configuration,
and the starting point of the M sub-frame #0 is the legacy
sub-frame #9. There are two sub-frames (4 ms) shift between the
legacy configurations of the configurations 2, 5 and the starting
point of the 0th sub-frame of the updated configuration: that is,
the starting point of the M sub-frame #0 is the legacy sub-frame
#8. Since the uplink and downlink configuration corresponding to
the legacy uplink and downlink configuration 6 is DSUUUDSUUD, it
cannot be represented by the special sub-frames shown in FIG. 12:
that is, the special sub-frames shown in FIG. 12 cannot support the
legacy configuration 6.
[0055] In another embodiment, different UL/DL configurations may
correspond to different design criteria. For example, one of the
above-described designs for the TDD system may be selected for
different UL/DL configurations, and then obtains more opportunities
for uplink and downlink transmission as much as possible and
improves system throughput. Furthermore, the system information may
be configured through the information bits in order to select the
design scheme. For example, the shift may be used in different
UL/DL configurations, and one bit in the SIB may be utilized to
represent whether the shift has been adopted or not. For example,
in some configurations, the special sub-frame may be processed
further. In a novel embodiment, for UL-DL configuration 1, a shift
may be added, which skips a particular sub-frame (e.g., 1 ms gap).
In another novel embodiment (e.g., for the UL-DL configuration 0
and the UL-DL configuration 2), the special sub-fame may be viewed
as 1 ms, and may be combined with the previous sub-frame or the
subsequent sub-frame to be one M sub-frame. While the above two
approaches may be predefined in, for example, the technical
specifications based on the corresponding UL-DL configuration. For
example, the further optimization of the above configuration can be
written to the technical specification, predefined in the system,
or separately configured in the SIB only. For the NB-IoT UE, the
above configuration may be transparent: that is, for different
starting points of frames, a shift such as 1 ms is used for the
legacy LTE UE. The same principle may apply to the transmission of
the MIB and synchronization signals, such as MBSFN. At the UE side,
if an indication, which is transmitted by the network side or the
base station, of a generated new frame structure is detected, then
the transmission can be performed by the frame structure. If the
indication of the frame structure indicates its change (e.g. by a
bit or an indication signal), the UE side may query or calculate
the frame structure for itself according to the indication on the
system side (such as defined in the technical specification,
hard-written, hard-coded, or a predefined table), and then it may
adopt the frame structure described in the above embodiments.
Embodiments of the above-described methods and frame structures may
be applicable to MTC, NB-IoT, or the UE limited by the new frame
structure described above, and the specific behavior will not be
described herein.
[0056] FIG. 14 is a flow diagram illustrating the network side that
generates the updated frame structure which is applied to different
UE according to one embodiment of the present disclosure. In step
1401, at the system side, such as a base station, or a core network
generates a first frame structure according to a first set of
parameters, wherein the first frame structure includes downlink
sub-frame, uplink sub-frame, and special sub-frame. Then in step
1402, a second frame structure is generated according to a second
set of parameters, wherein at least one of the three sub-frames,
which are the downlink sub-frame, the uplink sub-frame, and the
special sub-frame, in the second frame structure, differs from the
corresponding sub-frame in the first frame structure. Furthermore,
in step 1403, the first frame structure is used to serve a first
group of users, and the second frame structure serves a second
group of users. In one embodiment, the sub-frame length in the
second frame structure is an integer multiple of the sub-frame
length in the first frame structure in order to align the starting
points of the receiving/transmitting signals of the different users
as much as possible. Moreover, due to limited spectrum resources,
the base station can simultaneously serve different users with the
first frame structure and the second frame structure in different
frequency bands.
[0057] In one embodiment, the base station and the user may
generate one or more frame structures according to one or more of
the following parameters. The parameters are subcarrier spacing,
symbol length, cyclic prefix length, sampling rate, and FFT point.
As per the frame structure shown in FIG. 2, corresponding to the
frame structure, the subcarrier spacing is 15 kHz; the symbol
length is 6.67 us; the sampling rate is 30.72 MHz; the CP length is
144 sampling points (the first symbol has a CP length of 160
sampling points); another CP length is 512 sampling points; and the
FFT points are 2048. The length of one sub-frame is 1 ms, and the
sub-frame consists of 14 or 12 symbols. One slot is 0.5 ms and
consists of 7 or 6 symbols. Two slots may be a sub-frame. Five
sub-frames may be a half-frame. 10 sub-frames may be a system frame
which is 10 ms. Note that if the sampling rate of the system or the
system bandwidth is reduced, the number of sampling points of the
corresponding CP and the number of FFT point are reduced
proportionally, but the length of the symbol and the length of the
sub-frame are not changed. In another embodiment, as per the frame
structure shown in FIG. 3 (corresponding to the frame structure),
the subcarrier spacing is 3.75 kHz; the symbol length is 266.7 us;
the sampling rate is 240 kHz, the FFT points are 64; one CP length
is that the first symbol length is 8 sampling points (33.3 us), and
the remaining symbols are 4 sampling points (16.7 us); the other CP
length is that the first 4 symbols are 5 sampling points, and the
remaining symbols are 4 sampling points. In another embodiment, as
per the frame structure shown in FIG. 9 (corresponding to the frame
structure), the subcarrier spacing is 2.5 kHz; the symbol length is
400 us; the sampling rate is 320 kHz; the FFT points are 128; one
CP length is that the first symbol length is 9 sampling points
(28.125 us), and the remaining symbols are 5 sampling points
(15.625 us); the other CP length is that the first 4 symbols are 6
sampling points (18.75 us), and the remaining symbols are 5
sampling points (15.625 us).
[0058] In one embodiment, the second set of parameters further
includes the uplink parameter and downlink parameter: that is, the
uplink and downlink use different parameters which include one or
more parameters of the subcarrier spacing, symbol length, cyclic
prefix length, sampling rate, and FFT point. Furthermore, for a
user, the uplink and downlink may use different parameters to
define the frame structure. This definition is not limited to TDD
system, and may be applied to FDD system. As shown in FIG. 11 and
FIG. 12 (A), the downlink adopts a frame structure corresponding to
the subcarrier spacing which is 15 kHz, and the uplink uses the
different subcarrier spacing to correspond to the different frame
structure, such as a subcarrier spacing which is 3.75 kHz or 2.5
kHz. The user, the base station, or the core network generates a
second frame structure according to the second set of parameters
which further comprises: generating the uplink sub-frame based on
uplink parameters, generating the downlink sub-frame based on
downlink parameters, and generating the special sub-frame based on
uplink and downlink parameters. The uplink and downlink use
different parameters to generate the corresponding sub-frame. In
order to avoid generating interference with the user adopting the
first frame structure, some special M sub-frames need the special
sub-frame including at least two of the downlink symbol, uplink
symbol, and guard period. As shown in FIG. 10, the special M
sub-frame configuration 1 and the special M sub-frame configuration
2 have GP0 and GP1, wherein the GP1 makes the directions of the
uplink and downlink in the second frame structure coincide with the
directions of the uplink and downlink in the first frame
structure.
[0059] FIG. 15 is a flow diagram illustrating the method of
receiving and transmitting a signal at the base station side
according to one embodiment of the present disclosure. A method for
receiving and transmitting a signal, wherein the base station
supports a first sub-frame configuration and a second sub-frame
configuration. The method includes: Step 1501, the base station
generates a first frame structure by using the first sub-frame
configuration in a wireless network. In step 1502, the base station
generates a second frame structure by using a second sub-frame
configuration, wherein the sub-frame length in the second sub-frame
configuration is multiple times more than the sub-frame length in
the first sub-frame configuration. In step 1503, the base station
transmits the second sub-frame configuration to multiple UEs. In
step 1504, the base station uses the first frame structure and the
second frame structure to communicate with multiple UEs. If the
base station supports the first sub-frame configuration and the
second sub-frame configuration, then the method performs steps 1501
to 1504 described above. For a base station that only supports the
second sub-frame configuration, steps 1502-1504 are performed, and
step 1504 is further modified to communicate with multiple users by
using the second frame structure.
[0060] FIG. 16 is another flow diagram illustrating the method of
receiving and transmitting a signal at the UE side according to one
embodiment of the present disclosure. In this method, the user
equipment supports the updated sub-frame configuration, and the
updated sub-frame configuration can be identified. The method
includes step 1601, in which the UE receives the indication of the
second sub-frame configuration. In step 1602, the UE generates a
second frame structure according to the second sub-frame
configuration. In step 1603, the communication with the base
station is conducted according to the second frame structure.
[0061] In step 1602, the indication of the second sub-frame
configuration may be implemented as a simplified message (e.g., a
few bits) which supports or does not support the second sub-frame
configuration (for example). The second configuration may include
at least one of the subcarrier spacing, symbol length, cyclic
prefix length, sampling rate, FFT point, and offset.
[0062] In one embodiment, the first uplink and downlink
configuration may be the uplink or downlink configuration shown in
FIG. 2, or the second uplink and downlink configuration may be the
legacy UL-DL configuration shown in FIG. 4, FIG. 7, FIG. 8, or FIG.
13. In another embodiment, the second uplink and downlink
configuration may be the updated configuration as shown in FIG. 4,
FIG. 7, FIG. 8, or FIG. 13.
[0063] In one embodiment, the mapping relationship between the
first uplink and downlink configuration and the second uplink and
downlink configuration is predefined. For example, the mapping
relationship between the legacy configuration and the updated
configuration in FIG. 4, FIG. 7, FIG. 8, or FIG. 13. Similarly, the
mapping relationship between the first special sub-frame
configuration and the second special sub-frame configuration is
predefined, such as the mapping relationship between the legacy
special sub-frame configuration and the M special sub-frame
configuration shown in FIG. 5, FIG. 6, FIG. 10, FIG. 11, and FIG.
12. In another embodiment, the mapping relationship between the
first uplink and downlink configuration and the second uplink and
downlink configuration is obtained from the
mapping-relation-indication information. The base station may
deploy the user through system information or other RRC
information, or an indication of the physical layer, such as the
information of the downlink control information (DCI). In another
embodiment, the user obtains the first and second uplink and
downlink configurations through a combination of the predefinition
and indicated information. That is, the user equipment obtains the
indication of the first sub-frame configuration and the indication
of the second sub-frame configuration through the combination of
the predefinition and the indication information. Similarly, the
mapping relationship between the first special sub-frame
configuration and the second special sub-frame configuration may
also be obtained by the indication information or the combination
of the predefined relationship and indication information.
[0064] In another embodiment, the mapping relationship between the
first special sub-frame configuration and the special sub-frame
configuration is obtained according to at least two frame
structures of the first uplink and downlink configuration, the
first special sub-frame configuration, and predefinition.
[0065] While the invention has been described by way of example and
in terms of the preferred embodiments, it should be understood that
the invention is not limited to the disclosed embodiments. On the
contrary, it is intended to cover various modifications and similar
arrangements (as would be apparent to those skilled in the art).
Therefore, the scope of the appended claims should be accorded the
broadest interpretation so as to encompass all such modifications
and similar arrangements.
* * * * *